/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Copyright (C) 2015-2025 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

Class
    Foam::functionObjects::residuals

Description
    Writes out the initial residual for specified fields.

    Example of function object specification:
    \verbatim
    residuals
    {
        type            residuals;

        libs            ("libutilityFunctionObjects.so");

        writeControl    timeStep;
        writeInterval   1;
        fields
        (
            U
            p
        );
    }
    \endverbatim

    Output data is written to the dir postProcessing/residuals/\<timeDir\>/
    For vector/tensor fields, e.g. U, where an equation is solved for each
    component, the largest residual of each component is written out.

See also
    Foam::functionObject
    Foam::functionObjects::fvMeshFunctionObject
    Foam::functionObjects::logFiles
    Foam::functionObjects::timeControl

SourceFiles
    residuals.C

\*---------------------------------------------------------------------------*/

#ifndef residuals_functionObject_H
#define residuals_functionObject_H

#include "fvMeshFunctionObject.H"
#include "logFiles.H"

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{
namespace functionObjects
{

/*---------------------------------------------------------------------------*\
                          Class residuals Declaration
\*---------------------------------------------------------------------------*/

class residuals
:
    public fvMeshFunctionObject,
    public logFiles
{
protected:

    // Protected data

        //- Fields to write residuals
        wordList fieldSet_;


    // Protected Member Functions

        //- Output field header information
        template<class Type>
        void writeFileHeader(const word& fieldName);

        //- Output file header information
        virtual void writeFileHeader(const label i);

        //- Calculate the field min/max
        template<class Type>
        void writeResidual(const word& fieldName);


public:

    //- Runtime type information
    TypeName("residuals");


    // Constructors

        //- Construct from Time and dictionary
        residuals
        (
            const word& name,
            const Time& runTime,
            const dictionary& dict
        );

        //- Disallow default bitwise copy construction
        residuals(const residuals&) = delete;


    //- Destructor
    virtual ~residuals();


    // Member Functions

        //- Read the controls
        virtual bool read(const dictionary&);

        //- Return the list of fields required
        virtual wordList fields() const
        {
            return wordList::null();
        }

        //- Execute, currently does nothing
        virtual bool execute();

        //- Write the residuals
        virtual bool write();


    // Member Operators

        //- Disallow default bitwise assignment
        void operator=(const residuals&) = delete;
};


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace functionObjects
} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#ifdef NoRepository
    #include "residualsTemplates.C"
#endif

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //
